What does the Generate in-band DTMF option do, and why is it not recommended?
DTMF tones are the tones heard when pressing a standard analog telephone keypad. These tones are used to operate menus and voicemail systetms. By default VTALL sends DTMF tones out-of-band as messages to a DTMF enabled router which then transmits the tones through the PSTN. If you click the “Generate in-band DTMF” option VTALL mixes the DTMF tones into the audio stream. Select this option if you are using network hardware that does not respond to out-of-band DTMF messages. It is not recommended because the in-band DTMF is sometimes unreliable.
